It may be necessary to start a brushless motor at temperatures well below that of the normal running temperature. At relatively low temperatures, the viscosity of the grease within the bearings of the motor may hamper or prevent the motor from starting. Additionally, at sub-zero temperatures, icing may occur between the rotor and stator, which further hampers or prevents starting of the motor. Even if it is possible to start the motor, driving the motor under such conditions may damage components of the motor.
Schemes for preheating a motor are known but generally suffer from one or more disadvantages. For example, the motor may include a heating device that heats the motor to a predetermined temperature prior to starting. However, the provision of a heating device increases the cost of the motor.